Parent-Version:      0.50
Version-Log:

Change the way pre are translated in the .env file. Now
instead of writting "_pre2toto", one writes "pre(2,toto)".

But internally, it is handled the same way as before (i.e., the first
thing I do when parsing the env file is to transform "pre(2,toto)"
into "_pre2toto" (it makes the hangling of pre vars much more
homogeneous with the way the other vars are handled.

Also fix a bug where it was not possible to have a pre on input
vars because the update_pre was failing to proceed quietly  whenever
one of its var was not computable because its pre does have a value.
Also give an appropriate error message whenever the user wrongly
use a pre on a var that can not be computed.

Project-Description: Lurette